Chemical formula presents atom proportions using symbols and numbers. Formulae are not chemical names as they don't contain words. Chemical formulas can only specify simplest molecular structures
Hydrates contain water molecules in definite ratios as crystal components. Inorganic hydrates are salts bound to metal centers or crystallized with them. Water content is indicated by "hydrated compound⋅nH2O" notation. Anhydrides are hydrates that have lost water, requiring strong heating
O-xylene is a colorless, slightly oily flammable liquid with formula C6H4(CH3)2. It is a constitutional isomer of m-xylene and p-xylene. Petroleum contains about one weight percent xylenes
Organic compounds contain carbon-hydrogen or carbon-carbon bonds. Some authorities consider all carbon-containing compounds organic. Vitalism was once believed organic compounds formed from elements. Modern definition excludes certain traditionally considered inorganic compounds
Colorless liquid with sweet odor. Boiling point 181°F, melting point -154°F. Insoluble in water, less dense than water. Flash point 11°F, vapor density 2.8
Clear colorless liquid with petroleum-like odor. Boiling point 99.238°C, melting point -107.45°C. Density 0.69194 at 20°C, vapor density 3.93. Insoluble in water, vapor pressure 49.3 mmHg